Plate heat exchanger

Often referred to as a plate heat exchanger (PHE ) or plate cooler ( PK) - - A plate heat exchanger ( PHE ) is a special design of a heat exchanger. It consists of corrugated profiled plates which are assembled so that in each of the consecutive time intervals and then the reheating the heating medium flows. The plate package is sealed to the outside, and between the media and is held together for example by clamping screws.

Due to its special design ( screwed ) plate heat exchangers are very good expandable, and very flexible with regard to the configuration of the flow guide which is determined by the position of the seals.

Designs

A common design are brazed plate heat exchanger. In this design, the individual plates are soldered to one another, can be dispensed with so that the tensioning screws. In case of defects within the plate pack but individual plates can only be exchanged at the bolted design. Brazed plate heat exchanger must be completely renewed in such a defect.

Another design consists of laser-welded cassettes ( LWC = Laser Welded Cassette). Here two plates are welded with a laser to a gas-tight cassette, respectively. The plate pack is clamped with clamping screws so that dismantling or expansion is possible at any time. This design is particularly suitable for a critical medium ( welded gap) and a service medium ( sealed gap). In the plate heat an intensive heat transfer takes place, which can be further increased by turbulence in the flow. A turbulent flow is achieved in the first place by the profile of the plates.

Plate heat exchangers can be made very compact and have relative to their small size a very high heat flux, which is why they are used in various areas, including in the Industrieheiz, cooling and solar technology.

Cleaning

Due to the small distance between the plates, the flow is slightly hampered by contamination or even blocked. Soiling or calcification stuffy plate heat exchanger must be flushed or cleaned in a different manner.

Wherein rinsing is usually acidic solutions are used. In massive blockade of the bolted plate heat exchanger for cleaning into their component parts can be disassembled while the brazed plate heat exchanger must be replaced. Because of the risk of clogging up plate heat exchangers are suitable, for example, not as service water cooler or other media containing particles.

In district heating networks plate heat exchangers are often used for the separation of the primary circuit and the secondary circuit in the district heating supplied buildings. When milk production plate cooler or tube coolers are used to pre-cool the milk before it is actively cooled down in the cooling tank to the storage temperature.

See also: heat exchangers, heat transfer station

• Heat exchanger
• Dairy Equipment